This main newly developed high technology is the distinguishing part of the central driving the special toothed shape curve of sprocket adapting a rolling movement friction and rotating the power, emerging from previous traditional chain sprocket and bevel gear and this chilsung gear using shall change the history of traditional inconvenient chain Bike.
The durability and capability of riding is excellent and maintains steady status of power.

     This curved & toothod gear makes more easy to rolling connect between sprocket gear and taper-roller, which maintains quietness and precision requiring for bike and by small operation, it can convey of the power of moment effectively.